The present invention relates generally to the manufacture of book covers and particularly to the folding of the head, foot and lateral side flaps of a cover. More specifically, this invention relates to methods and apparatus for book cover assembly.
Book covers consist of a covering material, two cover boards and a spine board positioned between the two cover boards. The boards are glued to the covering material over their entire area. The covering material that projects beyond the cover profile defined by the three boards is turned in on all four sides. In the industrial manufacture of book covers, these operations are accomplished by book cover assembly apparatus.
In a known book cover formation machine, each book cover is manufactured in a series of operations performed sequentially in a single continuously executed machine cycle. The cut-to-size covering material, or cover cloth, is separated from a stack in a magazine and fed to a glue roller via a cloth cylinder. A gripper bar acquires the glue-coated cover cloth and deposits it on a cover table. Feeder elements push the cut-to-size cover boards from magazines and into a ready-use supply station, simultaneously with the infeeding of a spine board that has been cut to length from a reel.
The two cover boards and the spine board are picked up by a suction head, which is associated with a double-headed suction arm, and after said suction arm has rotated through 180.degree. , the boards are brought into contact with the glue-coated cloth which is lying on the cover table.
The cover table and suction arm thereafter move downwardly with the cover cloth and cover boards in two stages. On a first level, the projecting edges of the cover cloth on the so-called head and foot sides of the book cover are turned upwardly and then turned inwardly by means of a pair of turn-in rails. Additionally, the corners of the cover are drawn in by means of tools which are guided on side rails. The turning-up and turning-in, i.e., the folding, of the lateral cover flaps is performed on a second level, likewise by means of turn-in rails.
Simultaneously with the downward movement of the suction arm to the second level, a second suction head, mounted on the opposite side of the arm from the active head, acquires fresh cover boards that have been individually separated from the magazines, and the arm returns to its upper, starting position.
Finally, the cover table executes a downward movement, with the finished cover, to a third level. At the third level, a transport acquires the cover and feeds it to a pressing station, and the cover table likewise returns to its starting position in order to acquire the next cover cloth.